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Related papers: Multiband model for tunneling in MgB2 junctions

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Within the framework of non-stationary Ginzburg-Landau equations generalized on a case of two order parameters, we investigated dynamic characteristics of two-band superconducting MgB2 filaments in a voltage-driven regime. We calculated…

Superconductivity · Physics 2012-09-20 V. N. Fenchenko , Y. S. Yerin

We study macroscopic quantum tunneling (MQT) in c-axis twist Josephson junctions made of high-T_c superconductors in order to clarify the influence of the anisotropic order parameter symmetry (OPS) on MQT. The dependence of the MQT rate on…

Superconductivity · Physics 2009-11-13 Takehito Yokoyama , Shiro Kawabata , Takeo Kato , Yukio Tanaka

We study the effects of C substitutions in MgB_2 within the two-band model in the Eliashberg formulation. We use as input the B-B stretching-mode frequency and the partial densities of states N_{sigma}(EF) and N_{pi}(EF), recently…

Superconductivity · Physics 2009-11-10 G. A. Ummarino , D. Daghero , R. S. Gonnelli , A. H. Moudden

The progress in investigation of two-band superconductor MgB$_2$ by the point-contact spectroscopy (PCS) is given. Results of study of superconducting gap temperature and magnetic field dependence for two-dimensional $\sigma$ and…

Superconductivity · Physics 2007-05-23 I. K. Yanson , Yu. G. Naidyuk

We have constructed MgB2/Pb planar junctions for both temperature and field dependence studies. Our results show that the small gap is a true bulk property of MgB2 superconductor, not due to surface effects. The temperature dependence of…

Superconductivity · Physics 2009-11-07 Mohamed H. Badr , Mario Freamat , Yuri Sushko , K. -W. Ng

The superconducting circuits involving Josephson junction offer macroscopic quantum two-level system (qubit) which are coupled to cavity resonators and are operated via microwave signals. In this work, we study the dynamics of…

Quantum Physics · Physics 2022-07-12 Prashant Shukla

We have investigated the effect of unconventional pairing mechanism in MgB2 using a two-band model within the framework of Bogoliubov-Valatin formalism. The approach incorporates the intra- band s-wave interaction in the s- and p-bands, as…

Superconductivity · Physics 2017-06-22 O. C. Abah , G. C. Asomba , C. M. I. Okoye

We observe a subharmonic gap sturucture (SGS) and the Josephson effect in superconducting scanning tunneling microscope junctions with resistances below 100 kOhm. The magnitude of the n=2 SGS is shown to scale with the square of the…

Superconductivity · Physics 2007-05-23 O. Naaman , R. C. Dynes

Topological superconductors can support localized Majorana states at their boundaries. These quasi-particle excitations have non-Abelian statistics that can be used to encode and manipulate quantum information in a topologically protected…

We perform two-tone spectroscopy on quantum circuits, where high-frequency radiation is generated by a voltage-biased superconductor-normal-superconductor Josephson junction and detection is carried out by an ancillary microwave resonator.…

Mesoscale and Nanoscale Physics · Physics 2024-12-10 A. Peugeot , H. Riechert , S. Annabi , L. Balembois , M. Villiers , E. Flurin , J. Griesmar , E. Arrighi , J. -D. Pillet , L. Bretheau

Choi et al. [Phys. Rev. B 66, 020513 (2002)] recently presented first principles calculations of the electron-phonon coupling and superconductivity in MgB2, emphasizing the importance of anisotropy and anharmonicity. We point out that (1)…

Superconductivity · Physics 2007-05-23 I. I. Mazin , O. K. Andersen , O. Jepsen , A. A. Golubov , O. V. Dolgov , J. Kortus

The most important practical characteristic of a Josephson junction is its critical current. The shape of the junction determines the specific form of the magnetic-field dependence of the its Josephson current. Here we address the magnetic…

Superconductivity · Physics 2017-07-07 Roberto Monaco

The high-Q harmonic oscillator mode of a Josephson junction can be used as a novel probe of spurious two-level systems (TLSs) inside the amorphous oxide tunnel barriers of the junction. In particular, we show that spectroscopic transmission…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 L. Tian , R. W. Simmonds

We theoretically put forward the concept of a phase-controlled superconducting heat-flux quantum modulator. Its operation relies on phase-dependent heat current predicted to occur in temperature-biased Josephson tunnel junctions. The device…

Mesoscale and Nanoscale Physics · Physics 2012-10-02 F. Giazotto , M. J. Martinez-Perez

We study decoherence in superconducting qubits due to quasiparticle tunneling which is enhanced by two known deviations from the equilibrium BCS theory. The first process corresponds to tunneling of an already existing quasiparticle across…

Mesoscale and Nanoscale Physics · Physics 2012-04-20 Juha Leppäkangas , Michael Marthaler

We have observed multiphoton transitions between two macroscopic quantum-mechanical superposition states formed by two opposite circulating currents in a superconducting loop with three Josephson junctions. Resonant peaks and dips of up to…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 S. Saito , M. Thorwart , H. Tanaka , M. Ueda , H. Nakano , K. Semba , H. Takayanagi

There exists a large number of experimental and theoretical results supporting the picture of macroscopic qubits implemented by nanoscopic Josephson junctions of three different types -- charge qubit, flux qubit and phase qubit. The…

Superconductivity · Physics 2010-12-02 R. Alicki , W. Miklaszewski

We present a method to identify distinct tunneling modes in tunable superconducting tunnel junction composed of superconducting tip and sample in scanning tunneling microscope. Combining the measurement of the relative decay constant of…

Superconductivity · Physics 2021-09-22 Wonhee Ko , Eugene F. Dumitrescu , Petro Maksymovych

MiTMoJCo (Microscopic Tunneling Model for Josephson Contacts) is C code which aims to assist modeling of superconducting Josephson contacts based on the microscopic tunneling theory. The code offers implementation of a computationally…

Superconductivity · Physics 2020-03-31 Dmitry R. Gulevich

Tunneling amplitude through magnetic breakdown (MB) gap is considered for two bands Fermi surfaces illustrated in many organic metals. In particular, the S-matrix associated to the wave-function transmission through the MB gap for the…

Strongly Correlated Electrons · Physics 2017-04-05 Jean-Yves Fortin , Alain Audouard